Over the past three years, NOM has more than doubled from 146,800 persons in 2005-06 to a preliminary NOM estimate of 298,900 persons in 2008-09, the highest on record for a financial year. The increase is partially due to a change in methodology introduced after 30 June 2006. However, the main driver during this period has been the substantial growth in temporary visa arrivals to Australia's shores.

Temporary migration has become increasingly important with more international students, business entrants, working holiday makers and other long-term visitors staying in Australia for periods up to four years or more.

Australia's total population growth rate for 2008-09 was 2.1% with NOM contributing 1.4% to this growth.

During 2008-09, NOM contributed the greatest number of people to the most populous states: New South Wales with a net of 89,500 persons, followed by Victoria (81,200) and Queensland (58,000). The Northern Territory had the lowest with a net gain of 1,900 persons.

Population turnover due to overseas migration (gross overseas flows in relation to size of the population) was the highest in Western Australia in 2008-09 at 4.4%.

In 2008-09, persons aged 15-34 years comprised 67% of NOM compared to 28% of Australia's total population. Persons aged 0-14 years comprised 16% of NOM and 19% of Australia's population, and persons aged 65 years and over comprised just 0.3% of NOM but 13% of Australia's population.

An individual's actual true travel behaviour and associated characteristics are only available from final NOM data. Final NOM data can only be accurately recorded at the end of a 16 month reference period following a traveller's initial border crossing.

Based on final NOM data from 2007-08 (a net of 277,300 persons), temporary visa holders contributed by far the most to NOM with 67% (a net of 186,500 persons) of the total NOM figure for the year. At a distant second were permanent arrivals at 31% (a net of 86,400). New Zealand citizens contributed 13% (a net of 36,100) to NOM, whereas Australian citizens, with a negative input to NOM figures, contributed -7% (a negative net of -20,300) to NOM in 2007-08.

Traditionally, Australian citizens have a net negative input to NOM figures as more Australians depart from the country each year than return.

In 2007-08, international students made up the largest group of temporary visa holders contributing to NOM, resulting in a net of 108,700 students, or 39% of NOM for the year. Within this group of students, those travelling on higher education visas were the largest group contributing to NOM with 57,500 students representing 21% of the total NOM figure. The vocational education and training sector represented 10% (27,400 students) whereas all other student visas accounted for 9% (23,900 students) of the total NOM figure for 2007-08.

Of the countries of birth contributing to self reported temporary NOM arrivals in 2007-08, India added the most to the population with 43,100 persons arriving, followed by China (37,900 persons), the United Kingdom (28,200 persons) and New Zealand (23,600 persons).

Chapter 4 provides an overview of the recent changes undertaken to improve NOM estimation and reduce the large revisions to ERP.